<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
  //1.无参无返回值
  function f1() {
    console.log("f1");
  }
  //调用
  f1();
  //2.有参无返回值
  function f2(name,age) {
    console.log(name+":"+age)
  }
  f2("石昊",10000000000);
  //3.有参有返回值
  function f3(x,y) {
    return x+y;
  }
  f3(7,8);
  //4.无参有返回值
  function f4() {
    return 3*19;
  }
  f4();
</script>
</body>
</html>